fluke-worms, is most probably introduced in the juvenile condition into
the stomach by drinking unfiltered standing waters, and perhaps also by
eating vegetables which grow in wet places and upon which the young
fluke-worms may be encysted. From the stomach the worms gain access to
the portal venous system, within which they undergo development to
sexual maturity. The worms, proportioned to their number, {949}
occasion more or less sudden and dangerous hæmaturia. According to
Bilharz, who first discovered the parasite, it also induces
inflammation of the ureters, bladder, and rectum, accompanied with
ulceration and incrustations and concretions in the same, due to the
abundant deposit of eggs in the mucous membrane. The symptoms in the
hæmaturia are obvious; all treatment fails, but the prophylaxis is
evident.
* * * * *
AMPHISTOMUM HOMINIS.--The genus Amphistomum is distinguished from
Distomum in having the ventral disk placed at the posterior extremity
of the body.
A species has been recently described by Cobbold under the above name,
and is reported as having been observed several times in natives of
India. It is a red worm, about the fourth of an inch long, and inhabits
the cæcum and ascending colon, in which it was found in hundreds
together. The mucous membrane exhibited venous congestion and was
marked with numerous red spots resembling leech-bites, produced by the
parasites. One of the patients died of cholera.
We have too little information as to the symptoms induced by this
parasite, and of its treatment, to say anything. It is probable that
calomel, turpentine, and castor oil would be appropriate remedies.
Several other fluke-worms which have been reported as having been found
in the human body are generally viewed with doubt as to their
genuineness. Such are the Hexathyridium pinguicola, from a tumor of the
ovary; the H. venarum, said to have been found in the blood and in the
sputum of hæmoptysis; and the Tetrastomum renale, said to have been
found in the urine.
The Acanthocephali, or Thorn-head Worms.
The thorn-head worms in the mature condition are comparatively robust
cylindrical worms, with a body-cavity or coelum, but devoid of mouth
and alimentary canal. They are provided with a protrusile and
retractile proboscis-like head armed with circular rows of recurved
hooks, by which they firmly cling to the wall of the intestine of their
host. The sexes are distinct. There are many species, which mostly in
the mature state live in fishes. In the juvenile or larval condition
they live in other animals, mostly crustaceans and insects. It is
doubtful whether any species naturally infests man.
* * * * *
ECHINORHYNCHUS GIGAS.--The great thorn-head worm is a common parasite
of the hog, living in the small intestine. It is a large white worm,
the female of which reaches a foot in length, while the male is about
one-third the size. It is doubtful whether it occurs as a human
parasite, though a worm less than the fourth of an inch found in a man
in Prague has been attributed to this species.
The Nematodes, or Thread-worms.
The nematodes, or thread-worms, are slender, cylindrical, and
inarticulate, and usually more or less tapering toward one or both
extremities. {950} They have a distinct coelum or body-cavity, with
thick muscular walls limited by a transparent elastic, chitinous
integument, which is sometimes more or less distinctly and regularly
transversely wrinkled. The alimentary canal extends the length of the
coelum, with the mouth at the anterior extremity, and usually an anus
at or near the posterior extremity. In some forms in the mature
condition the intestine is atrophied and the anus absent. The sexes are
distinct, and commonly the male is very much smaller than the female.
The organs of generation occupy the coelum along the sides of the
intestine. The female aperture is commonly situated ventrally near or
in advance of the middle of the body, while the male aperture is at or
in the vicinity of the anus. Mostly, the worms are oviparous, but many
are viviparous. The development is direct, and usually the
transformations are inconspicuous, so that the embryos mostly differ
but little from the parent, except in the absence of the generative
apparatus.
* * * * *
OXYURIS VERMICULARIS.--SYNONYMS: Ascaris vermicularis; Seat-worm;
Pin-worm; Maw-worm; Maggot-worm; Thread-worm; Ascarides.
The seat-worm is the most common intestinal parasite of man, prevails
everywhere, and is peculiar to him. It is a lively, wriggling creature
which inhabits the small and large intestines and feeds on their
contents. It frequently occurs in large numbers together, and in such
cases incessantly makes its appearance, associated with multitudes of
eggs, in the evacuations.
The female, which is ordinarily seen alone in the greatest abundance,
is a white cylindrical worm tapering toward both extremities. The head
end is thickened, and is provided with three prominent labial papillæ
enclosing the mouth. The posterior end extends from the anal aperture
in a long and straight, narrow, conical, sharp-pointed tail. The double
uterine tube, distended with eggs, terminates in a vagina, the external
aperture of which is situated ventrally near the anterior third of the
body. The smaller male hardly tapers behind, but is incurved and ends
in a short, blunt, conical tail. The penis is a single chitinous
spicule, the end of which is usually seen projecting from the cloacal
aperture.
The young seat-worms, in various degrees of growth and development, and
the mature males are chiefly to be met in the lower portion of the
small intestine, while the pregnant and mature females chiefly occupy
the cæcum.
The seat-worm is exceedingly prolific, it being estimated that a single
ripe female contains from 10,000 to 12,000 eggs, and these, it is
suspected, may be renewed several times before her functions become
exhausted. From time to time the ripe females proceed along the large
intestine to the rectum, in which position they lay most of their eggs.
These are discharged, together with many of the worms, in the feces.
The eggs are ovoid in shape and about 0.05 mm. long. After they are
laid under favorable conditions the embryos are rapidly developed. Left
in water, they soon die.
The investigations of the helminthologists of the day make it appear
that it is necessary that the eggs of the seat-worm should be swallowed
{951} and pass through the stomach, in which the embryos are freed,
before they can undergo development to sexual maturity. Moreover,
observations go to show that infection may, and probably ordinarily
does, occur from eggs scratched from the anus and conveyed to the mouth
directly or by being applied to food from uncleanly hands. It is
evident that itching of the anus, induced by the presence of the
parasites in the rectum, often accompanied by itching of the nose and
lips, may lead to alternate scratching of the parts and the
transference of eggs from one to the other. Thus, too, uncleanly nurses
who may be infested with seat-worms after scratching may handle food
and infest children under their charge. Children are commonly more
liable to the parasites than others, no doubt from the circumstance
that they are less capable of avoiding the conditions favorable to
infection. Seat-worms prevail in all conditions of society, but their
prevalence is largely proportioned to the more or less uncleanly
habits. Persons sleeping with others infested are liable to infection,
especially if they are uncleanly and in the habit of eating in bed.
Obvious hints to avoid the parasites are obtained by regarding the
statements thus given.
SYMPTOMS.--The presence of a few seat-worms is usually attended with no
obvious inconvenience, and they may remain unnoticed unless
accidentally observed in the evacuations. The symptoms occasioned by
them are in great measure proportioned to their quantity and the
susceptibility of the patient. The most prominent symptom is excessive
itching of the anus; often trifling or even absent during the day, it
becomes very annoying and distressing in the evening or during the
night. This periodic change appears to be due to the movement of the
worms to the rectum, apparently induced by the position and repose of
the patient and the increased warmth of the body in bed. Under these
circumstances the patient attempts to relieve the incessant itching by
scratching, and often by boring with the finger in the anus. In this
way eggs become adherent to the finger-nails, under which they have
been repeatedly detected, and may thus be inadvertently transferred to
the mouth. Occasionally, some of the worms wander from the anus, and in
women may thence penetrate into the vulva. The itching of the anus may
induce more or less sexual irritation, which in the young may further
lead to onanism and its attendant evils. Other symptoms of the presence
of the parasites are itching of the nose and lips, restlessness in
sleep, grinding of the teeth, startings, twitchings, and general
nervous disturbance. When the worms are very numerous they may produce
intestinal catarrh, with discharges of mucus, pain, and diarrhoea. In
children especially they may give rise to more serious nervous
symptoms, as epileptic fits and chorea.
TREATMENT.--Generally, persons are readily relieved of seat-worms.
Epsom salt alone or with senna as a purgative, repeated once or twice,
often answers to completely expel them. Castor oil, also alone or with
a few drops of the oil of turpentine or of wormseed, is also an
effectual remedy. The tincture of aloes, in the dose of from half a
fluidounce to two fluidounces, once or twice repeated, the writer has
found to fully answer the purpose. Besides the purgatives, medicated
suppositories, in obstinate cases injections of olive oil, and enemata
of a solution of castile soap introduced by means of an elastic tube,
so as to wash out the entire length of the large intestine, may be
employed.
* * * * *
{952} ASCARIS LUMBRICOIDES.--SYNONYMS: Round-worm; Long round-worm;
Maw-worm; Lumbricus.
The round-worm is the largest of the nematodes which ordinarily infest
man, and is second only in frequency to the seat-worm. It is a
well-known parasite, and prevails everywhere in all conditions of
society. It is less lively in its movements than the seat-worm, and is
remarkable for possessing a peculiar disagreeable odor, which is
independent of the medium in which it lives. It inhabits the small
intestine and feeds on the contents. It also infests the hog and the
ox.
The round-worm is cylindrical, reddish or brownish, and tapering toward
both extremities. The head end terminates in three prominent labial
papillæ surrounding the mouth, and the tail end is short and conical.
The female, as commonly seen, ranges from six inches to a foot in
length, and is about a fourth of an inch in thickness. The ovarian
tubes are long, thread-like, and tortuous, and, with the shorter,
nearly straight, and wider uterine tubes, contain many millions of
eggs. The genital aperture is situated ventrally near the anterior
third of the body. The male is about half the size of the female, but
is capable of considerable extension, and the tail end is incurved. The
penis consists of a pair of slender, clavate, chitinous spicules, the
ends of which protrude from the cloacal aperture at the root of the
tail.
The round-worm is exceedingly prolific, it being estimated that the
genital tubes of a large mature female contain the enormous number of
60,000,000 of eggs. The ripe eggs are laid in the intestine, and are
discharged with the evacuations in great numbers, and often in
considerable masses together. They are oval, about 0.05 mm. in length,
and are provided with a thick shell and an additional tuberculate
albuminoid envelope, usually colored by the intestinal contents.
The eggs of the round-worm after being expelled from the body are very
tenacious of life, and under ordinary favorable circumstances they may
remain in a condition capable of development for several years.
Experiments have shown that they have great power in resisting the
destructive influences of heat and cold, dryness, and the agencies of
decomposition. In water and moist earth they have been retained alive
for a year or two. When ripe eggs are placed in water the development
of the embryo is observed to proceed very slowly, and is only completed
after five or six months. The embryo while still contained within the
egg sheds its skin and becomes provided with a tooth-like spine to the
head end. The smallest examples of reputed round-worms found in the
human intestine measured only about a line in length.
The further history of the round-worm is unknown, nor has it yet been
positively ascertained in what manner man becomes infected with the
parasite. Repeated experiments, not only on the hog and other animals,
but on man himself, go to show that he is not directly infected by
swallowing the recently-laid ripe eggs. It is rendered probable that
the eggs are swallowed by some common but yet unknown minute aquatic
animal, within which the embryo may undergo further development, and in
this condition may be swallowed by man in drinking-water. In
confirmation of the view that man becomes infected in the latter way,
Davaine remarks that the "people of Paris, who drink only filtered
{953} water, are rarely infected with the round-worm, which is
otherwise the case in the rural districts of France."
The round-worm is most prevalent in warm climates, and especially among
the less-civilized peoples. The better classes among the more
enlightened nations suffer comparatively little from the parasite, and
it is the lower classes, especially the ill-fed and uncleanly, who are
most afflicted. It is exceedingly frequent in the Orient, in Africa,
the West Indies, and Brazil.
Most commonly, only a few round-worms--one, two, three, up to a
dozen--occur together in the same person, but they often occur in
considerable number, even to several hundreds. Not unfrequently they
are found in association with seat-worms. They are more frequent and
usually occur in greater abundance in children, perhaps in a measure
due to the circumstance that they are less able to discriminate the
conditions favorable to infection and avoided on other grounds by
adults.
The natural and ordinary habitation of the round-worm is the small
intestine, especially the jejunum, and it commonly only occurs in the
large intestine, mostly dead, on the way to be discharged with the
evacuations. Under disturbing circumstances, as the character of
certain irritating food, the parasite is disposed to become restless
and wander from its usual position. Not unfrequently it enters the
stomach, and thence may ascend to the mouth or nose, and perhaps the
first intimation of the presence of such an unwelcome guest is in its
expulsion from the mouth. From the pharynx the worm may enter the
larynx and trachea, or advance farther into the air-passages, giving
rise to the usual symptoms of foreign bodies in these parts.
Occasionally the parasite forces its way through the bile-ducts into
the liver and gall-bladder, creating disturbance in those organs
proportioned to the number and size of the worms and the extent of
their progress. In the liver it may occasion inflammation and the
formation of an abscess attended with all the usual symptoms of
hepatitis. It has been reported that it may penetrate the intestinal
wall and enter the peritoneal cavity, but it is generally regarded as
doubtful whether the worm can do so in a healthy state of the
intestine, but only where there may be ulceration or other similar
condition.
SYMPTOMS.--The symptoms indicating the presence of the round-worm in
the intestine vary with its numbers and with the age and susceptibility
of the patient. In general, the presence of one or two worms is
unattended with any marked disturbance, and is mostly unsuspected until
the parasite is accidentally seen in the discharges. The ordinary
symptoms are disordered appetite (usually increased), flatulence,
hiccough, foul breath, dyspepsia, abdominal pains, itching at the
extremities of the alimentary canal, furred tongue, darkening of the
eyelids, and emaciation. The nervous symptoms are restlessness in
sleep, unpleasant dreams, starting in fright, grating of the teeth, and
muscular twitchings. In more aggravated cases, especially in children,
epileptic fits may occur. If the parasites are numerous, they produce
diarrhoea with copious mucus discharges, and may induce enteritis with
all its attendant symptoms. When the worms wander into the stomach,
they induce colic, nausea, retching, and vomiting, all of which
disappear with the expulsion of the parasites.
TREATMENT.--The remedies employed for seat-worms often serve to {954}
expel the round-worm, and not unfrequently the two are discharged
together. Wormseed, or the seed of Chenopodium anthelminticum, has been
a favorite remedy for the round-worm, especially in children. The dose
in these cases is one or two scruples of the powdered seeds in
electuary with syrup or molasses, administered in the morning before
breakfast and at bedtime for three or four days. It should be followed
by calomel or other brisk cathartic. The volatile oil, in the dose of
from five to ten drops in emulsion, may be used in the same manner.
A much-extolled remedy to destroy and get rid of the round-worm is
santonin, given in doses of from one-third to one and a half grains
three or four times a day, the larger dose being used only for adults.
It should be followed by a purgative, for which a dose of castor oil
answers a good purpose.
* * * * *
ASCARIS MYSTAX, the common round-worm of the cat and dog, has been
reported as occasionally infesting man. It resembles the former
species, but is much smaller, commonly from one to four inches in
length, and has the head end furnished with a pair of lateral narrow,
wing-like expansions of the integument. It inhabits the small
intestine, and when present in man would no doubt induce symptoms like
those of the ordinary round-worms which infest him.
* * * * *
TRIOCEPHALUS DISPAR.--SYNONYMS: Long thread-worm; Whip-worm.
The long thread-worm is a not unfrequent intestinal parasite of man,
though rarely observed unless specially sought, as it ordinarily gives
rise to little or no disturbance. It is common in England, Southern
Europe, and the Orient. Davaine reports that half the cases of persons
investigated in Paris were infested with it; it also occurs in this
country. It inhabits the lower end of the ileum, the cæcum, and
vermiform appendix, and feeds on the intestinal contents. It commonly
occurs in small numbers, two or three to a dozen, occasions no evident
inconvenience, and is rarely discharged with the evacuations.
The long thread-worm is yellowish-white and cylindrical, with the
anterior half or more of the body attenuated in a hair-like manner. The
female reaches about two inches in length, has the tail end conical,
and the anus subterminal. The male is about two-thirds the length of
the former, has the thicker portion of the body enrolled, and the tail
end blunt. The eggs are laid in the intestine and discharged with the
feces. The subsequent history of the parasite and its mode of infecting
man remain unknown.
Only in cases where long thread-worms are numerous do they give rise to
trouble. According to Leuckart, Pascal gives as constant symptoms of
the presence of large numbers of the parasite, headache, redness of the
face, prominence of the eyes, small, irregular, and intermittent pulse,
and pains in the lower part of the abdomen.
The usual remedies addressed to the seat-worm and round-worm will most
probably be equally applicable to the long thread-worm.
* * * * *
LEPTODERA STERCORALIS.--SYNONYMS: Anguillula stercoralis; Rhabditis
stercoralis.
{955} This is a minute nematode worm recently observed infesting French
soldiers in Cochin China. It is about half a line in length, and
inhabits the small and large intestine, and also penetrates into the
biliary and pancreatic ducts. It occurs in myriads and occasions
diarrhoea and dysentery. Another species, Leptodera intestinalis,
nearly three times as large, has been noticed in smaller number
associated with the former. The eggs of these worms are laid in the
intestines, and both together are discharged in multitudes with the
feces. They are probably introduced into man by drinking stagnant
water, and undergo complete development after passing through the
stomach.
It is probable that the remedies employed in the treatment of the
familiar seat-worms and round-worms would be equally efficacious in the
expulsion of these parasites.
* * * * *
ANCHYLOSTOMUM DUODENALE.--SYNONYMS: Strongylus duodenalis; Dochmius
duodenalis; Sclerostoma duodenale.
This intestinal parasite, first noticed in Milan by Dubini in 1838, is
of more dangerous character than any of the nematode worms previously
described. In Europe, besides Italy, it was frequently observed among
the workmen of the St. Gothard tunnel. It is exceedingly common in
Egypt, and Bilharz found it in nearly all his post-mortem examinations
of bodies. It probably prevails to a considerable extent in most
tropical countries, including the East and West Indies and Brazil.
There is also reason to suspect, from the nature of the affection it
induces, that it may exist in the Southern States.
The Anchylostomum is a red, cylindrical worm, with the anterior
extremity tapering and recurved. The head end, somewhat enlarged,
encloses a capacious oral capsule armed with strong hook-like teeth.
The caudal extremity of the female ends in a conical point, and the
genital aperture is situated behind the middle of the body. The caudal
extremity of the male ends in a trilobate pouch, within which projects
the bispiculate penis. The female is from five lines to three-fourths
of an inch long; the male is about half the size. The eggs are oval and
measure 0.05 mm. long.
The worm inhabits the small intestine, especially the duodenum and
jejunum, clinging tenaciously to the lining membrane by means of the
armed mouth. It penetrates the mucous membrane to the submucous coat,
from which it sucks the blood that forms its food. In the position of
its attachment it gives rise to little ecchymoses. It often occurs in
large numbers, even to hundreds and thousands. The eggs are laid in the
intestine and are discharged with the evacuations. Externally, in
water, the embryo undergoes development within the egg, and then
escapes to lead for some time an independent existence. Subsequently,
it is most probable that the worm obtains access to the human stomach
by drinking standing water, and completes its development in the
intestine.
The Anchylostomum proves to be a prolific source of wasting diseases in
tropical countries, and is pernicious to an extent proportioned to the
numbers infesting the intestine. By depriving the body of blood it
produces a greater or less degree of anæmia. The affection begins very
insidiously, and the general nutrition of the body may not be visibly
disturbed {956} until a late period. In moderate cases the disease is
indicated by general paleness of the skin and mucous membranes, fatigue
on slight exertion, and a tendency to palpitations and quickened pulse.
In more severe cases there is constantly increasing debility, with
increase of paleness, indisposition to exertion, excessive sleepiness,
and feeling of coldness. Dyspeptic symptoms sometimes appear, and loss
of appetite may alternate with ravenous hunger. Accompanying this there
is often a disposition to eat innutritious articles, as coal, clay,
wool, etc. Feeling of weight and oppression in the epigastrium and
abdominal pains are frequent. In the advance of the affection shortness
of breath appears, increased on exertion to violent dyspnoea.
Emaciation becomes obvious in the later stage of the disease. In the
worst cases the symptoms increase in severity, the patient becomes
dropsical, is attacked with profuse diarrhoea and vomiting, and finally
dies.